31
VENTING SYSTEM
Vent system is very important part of heating system.
No boiler, however effi cient its design, can perform
satisfactorily if chimney that serves it is inadequate. Check
your chimney to make sure that it is right size, properly
constructed, clean and in good condition to ensure proper
combustion and THAT NO HAZARD WILL DEVELOP You
must also provide enough FRESH AIR FOR COMBUSTION.
LACK OF ENOUGH OXYGEN WILL CREATE A HAZARD. If
your building is of tight construction, it may be necessary
to add FRESH AIR DUCT to provide OXYGEN required
(Refer to Chart 2 in the front of this manual).
Cleaning The New Steam Boiler
New steam boilers must be cleaned previous to or during
the fi rst few days of use in order to ensure effi cient
operation. The grease or oil used to lubricate the cutting
tools or push nipples during the erection of new piping
systems picks up sand and dirt causing a scum of fi ne
particles and grease to accumulate on the surface of the
water in all new boilers, The heavier particles carried in
the grease may settle to the bottom of the boiler and
form sludge. This condition, if permitted to remain in
the boiler, tends to prevent the generation of steam,
produces foaming and causes an unsteady water line.
This unavoidable accumulation of oil and grease should be
removed by blowing off the boiler as follows:
1.
Install a surface blow-off connection of at least 1¼’
nominal pipe size in boiler using the Skimming Tee
shown in
Figure 35. The blow-off line should extend to
within 18” of the fl oor or to the sewer.
A. Insert a valve in the line close to the boiler.
2.
Bring the water line to the center of the outlet.
A. Raise the temperature to a point just below
steaming.
B. While the burners are on, open the valve in the
skim line and then slowly feed clean water into the
boiler adjusting the inlet water so that the boiler
water remains hot.
C. Continue skimming until the water is clean.
3.
Close valves in boiler feed line and skim line.
4.
Bring the pressure in the boiler to about 10 lbs.
A. Turn off the burners.
B. Open the bottom drain valve permitting all the
water to drain from boiler.
5.
After the boiler has cooled, fi ll and fl ush out several
times.
6.
Fill to proper water level and ready for normal service.
NOTE: Use of soda or any alkali, vinegar or any acid is not
recommended for cleaning heating boilers because it is
diffi cult to completely remove them and injury may occur
after the cleaning process has been completed.
Boiler Water Treatment
In closed hot water heating systems, negligible amounts
of make up water are used, and water treatment is not
required.
In steam systems where the system is tight, free from
leaks, and all the steam is returned to the boiler as conden-
sate, the amount of make up water is small. Again, water
treatment is not required.
On steam systems with less than 90% of the steam be-
ing returned as condensate, or with very hard or corrosive
make up water, treatment may be desirable. Follow the rec-
ommendations of the ASME (American Society of Mechani-
cal Engineers) Boiler and Pressure Vessel Code, Section VI,
latest version.
Between Heating Seasons
Boilers should not be drained between heating seasons.
Boilers in closed hot water heating systems may be left as
is. Steam boilers should be entirely fi lled with water during
the summer months to exclude air.
Low Water Cutoff(s)
Inspect low water cutoff(s) annually or as recommended
by low water cutoff manufacturer. Flush fl oat types per
manufacturer’s instructions.
General Housekeeping
• Keep boiler area clear and free from combustible
materials, gasoline and other fl ammable vapors and
liquids.
• Keep boiler area clear of obstructions to fl ow of
combustion and ventilation air.
CHECKING AND ADJUSTING
CLEANING AND MAINTENANCE
AT LEAST ONCE A MONTH DURING HEATING SEASON
check to see that sections of vent pipe are secure at all
joints and fi ttings. There should be at least two (2) sheet
metal screws per joint.
Check to see that vent pipe slopes at least 1/4” per foot
up from boiler to chimney. Vent pipe should be securely
fastened to prevent sagging.
Vent Pipe should also be checked for any deterioration
from corrosion or any other sources. Refer to Venting and
Combustion Air instructions in the front of this manual.
